HYENA
The Hyaenidae is a mammalian family of order Carnivora. The Hyaenidae family, native to both African and Asian continents consists of four living species, the Striped Hyena and Brown Hyena (genus Hyaena), the Spotted Hyena (genus Crocuta) and the Aardwolf (genus Proteles).
Hyenas seem to have originated 26 million years ago from arboreal ancestors bearing similarities to the modern Banded Palm Civet. Plioviverrops, one of the earliest hyenas, was a lithe civet-like creature that inhabited Eurasia 20-22 million years ago. Details from the middle ear and dental structure marked it as a primitive hyena. This genus proved successful, its descendants flourishing with more pointed jowls and racier legs, much as the Canidae had done in North America. Fifteen million years ago, dog-like hyenas flourished, with 30 different species being identified. Unlike some of their modern descendants, these hyenas were not specialized bone-crushers, but were more nimble, wolf-like animals. The dog-like hyenas had canid-like molars, allowing them to supplement their carnivorous diet with vegetation and invertebrates.
Hyenas seem to have originated 26 million years ago from arboreal ancestors bearing similarities to the modern Banded Palm Civet. Plioviverrops, one of the earliest hyenas, was a lithe civet-like creature that inhabited Eurasia 20-22 million years ago. Details from the middle ear and dental structure marked it as a primitive hyena. This genus proved successful, its descendants flourishing with more pointed jowls and racier legs, much as the Canidae had done in North America. Fifteen million years ago, dog-like hyenas flourished, with 30 different species being identified. Unlike some of their modern descendants, these hyenas were not specialized bone-crushers, but were more nimble, wolf-like animals. The dog-like hyenas had canid-like molars, allowing them to supplement their carnivorous diet with vegetation and invertebrates.
Five to seven million years ago, the dog-like hyenas were outcompeted by canids traveling from North America to Eurasia via the Bering land bridge. The ancestral aardwolves survived by having adapted themselves to an insectivorous diet to which few canids had specialized. Some hyenas evolved bone crushing teeth which allowed them to avoid competition with the canids, resulting in the hyenas eventually outcompeting a family of similarly built bone crushers called "percrocutoids". The percrocutoids became extinct 7 million years ago, coinciding exactly with the rise of bone crushing hyena species. Unlike the canids who flourished in the newly colonized Eurasian continent, only one hyena species, the cheetah-like Chasmaporthetes managed to cross to North America. It became extinct 1.5 million years ago.
The peak diversity of the Hyenidae was during the Pleistocene, with 4 genera and 9 species of hyena. The bone crushing hyenas became the Old World's dominant scavengers, managing to take advantage of the amount of meat left over from the kills of sabre-toothed cats. One such species was Pachycrocuta, a up 200 kg (440 lb) mega-scavenger that could crush elephant bones. As the sabre-toothed cats began to die out and be replaced by short-fanged felids which were more efficient eaters, more hyenas began to hunt for themselves and began evolving into new species, the modern spotted hyena being among them.
